Gender and anatomy ultrasound tomorrow help

I'm scheduled to have my 18 week anatomy and gender ultrasound. I am very anxious, nervous, I hope I can sleep and I don't want to let my family down. Everyone wants a girl especially my only dd who has two brothers already and all the cousins are boys which leaves her alone. I have a feeling it's a boy just because that's usually how it works. I will be torn up inside to have to tell her and my other kids and family if  it's a boy. Any suggestions or ideas to make tomorrow go more smoothly would be a great help. And I will update tomorrow on the revealing.